Antenna Installation
4
Top-mounted support pipe
If your support pipe is mounted on top of a tower or building, locate the
antenna with at least ten feet (3.1 m) of vertical clearance between the bot-
tom antenna bay and the top of the tower or building. Then mount the pipe in
accordance with the guidelines above.
Installing the radiators
Radiators are mounted to the support pipe by means of formed mount chan-
nels (
Figure 2
). One formed mount channel is required for each bay without
radomes (
Figure 3
on page 5); two channels for a bay with radomes (
Figure 5
on page 6).
Figure 2. Formed mount channel
Important!
Feedstrap orientation is critical to performance. In general, all the feed-
straps in a Model 6812B antenna will be oriented the same.
Install each
radiator in accordance with its stenciled bay numbers and its "up-arrow"
sticker.
Also, be very careful not to disturb or damage the feed strap when han-
dling the radiator.
CAUTION
Radiators are stenciled with their respective bay numbers (bay #1 is the
topmost bay). Install the radiators in accordance with their match-mark-
ings. If you don’t, the antenna may not perform as expected.
Installation procedure
a. Remove any paint or corrosion on the support pipe where the formed mount
channel will be located, to ensure good electrical contact.
b. Position radiator #1 at the topmost mark you made on the support pipe.
c. (Antennas without radomes) Using the U-bolt, nuts, and washers, clamp the
formed mount channel and the radiator assembly to the support pipe, as
shown in
Figure 3
on page 5.
NOTE
Radomes are pre-installed and need not be removed for installation.
CAUTION
Install the backplate with the long slots at the top, as shown in
Figure 4
on page 5.
d. (Antennas with radomes) Using two U-bolts with nuts and washers, clamp
two formed mount channels, a backplate, a spacer, and the radiator/radome
assembly to the support pipe, as shown in
Figure 5
on page 6.
e. Repeat for the remaining radiators, ensuring they are in the proper sequence
and oriented correctly per the installation drawing.
